Improving Fiber Quality Traits of Xinluzao 45 Using Gossypium barbadense Chromosome Segment Substitution Lines

Gossypium barbadense chromosome segment substitution lines could be used as an important germplasm resource for improving fiber quality traits of upland cotton. In this study, we used TM-1 background substitution lines CSSL-122, the Xinjiang upland cotton Xinluzao 45 and hybrid, backcross progeny BC₂F₁ populations comprising 120 individual plants as test materials. Nineteen SSR markers located in Gossypium barbadense chromosomes land inked with fiber length and strength were used to screen out obvious polymorphic primers between the parents. We then traced and detected chromosome segments of Gossypium barbadense in the BC₂F₁ populations. Simultaneously, we compared fiber quality traits of positive plants that contained Gossypium barbadense chromosome segments with non-positive plants in the BC₂F₁ populations. The results showed that two markers, NAU2987 and BNL3145, which were linked with fiber length, could accurately identify the positive plants. In addition, compared with non-positive plants, the increased fiber length and strength of the positive plants were very significant (P < 0.01). Our research suggested that alien Gossypium barbadense chromosome segments significantly improved the fiber quality traits of Xinluzao 45. Thus, the Gossypium barbadense chromosome segment substitution lines will provide a vital theoretical basis and practical reference for improving Upland Cotton fiber quality traits.